After creating the list on the web, your iOS device, or your Mac, click the icon next to the list that looks like a Wi-Fi icon (strangely, it doesn't use the traditional sharing icon nor does the icon show up in iOS 7). Type in the name of another iCloud user, and you'll both have access to the reminders.

This comes in handy when you need to remember something at a specific location like the grocery store, but aren't sure which of you will get there first. It's a pretty basic tip, but one I just started using—and it's a lot more handy than I'd realized.